1.   The currents leaving the delta connection will have a value that is determined by the vector sum of the currents that make up the delta connection. When compared to wye currents, this value is increased by a factor of the ________ .

     a.    Square root of 3

     b.    CT ratio

     c.    Cosine of theta

     d.    Square root of 5

2.   The secondary circuits of current transformers in service are never to be _________ .

     a.    Opened

     b.    Shorted

     c.    Grounded

     d.    Jumpered

3.   A test switch on a current transformer does not _________ .

     a.    Allow the secondary circuit to be opened

     b.    Provide easy access to the instruments

     c.    Permit the permanent circuit to be isolated and the instruments tested and calibrated using a standardized test plug

     d.    Allow the current in the circuit to be read while in service easily and safely

4.   CT Polarity may be observed when using a _________ .

     a.    Phase angle meter

     b.    Shunt tester

     c.    Clamp-on ammeter

     d.    Phase separator

5.   The primary current of a CT will be reproduced in the secondary in proportion to the __________ .

     a.    CT ratio

     b.    Length of the primary wire

     c.    Ambient temperature

     d.    Weight of the CT

6.   For wye connected current transformers I pri = I sec x CTR. If I sec = 6.2 and CTR = 600/5. Then I pri equals ________ .

     a.    744 amps

     b.    740 amps

     c.    6.2 amps

     d.    600 volts

ANSWER KEY

Determining current in a circuit

This exam covers the following lessons:

         Determining current in a circuit